Telegraph-circuit.



J. J. GHEGAN.

TELEGRAPH CIRCUIT.

APPLICATION FILED MAY], m4.

I I FI I i] wue/wto c COLUMBIA PLANOGRAPH CO.,\VASHINGTON. D. c.

r ens JOHN J. GHEGAN, 0F NEWARK, NEW JERSEY.

TELEGRAPH-CIRCUIT.

Specification of Letters Patent. Patented Aug, 31, 1915,

Application filed May 7, 1914. Serial No. 836,876.

To all whom it may concern Be it known that 1, JOHN J. GI-IEGAN, a citizen of the United States, residing in Newark, in the county of Essex and State of New Jersey, have made certain new and useful Improvements in Telegraph-Circuits, of which the following is a specification.

This invention relates to simple telegraph circuits where signals are transmitted by making and breaking the circuit; in such circuits, usually, the battery is in two sections, at separated terminal points, and there are one or more intermediate stations. The two stations at the terminals are under the constant care' of operators who frequently adjust the relays, but at the intermediate stations operators attend only on call, and when there is an escape or leak between one terminal station and'an intermediate station the intermediatestation relay gets out of adjustment and it becomes diflicult and sometimes impossible to call, efiectively, for the attention of the intermediate station operator. This is because while the battery connection is broken at one terminal, the other section of the battery, at the other endof the line, leaks to ground through the escape and holds the armature in its attracted position against the effort of the retracting spring to withdraw it.

The object of this invention is to obviate the difficulties above indicated and to simultaneously open the circuit at both terminals. The improvement consists in providing an inductorium at the terminal station which, when the current is broken at one terminal point, the break, inductively influences an extra relay having its back contact points in series in the main line; This operates to kick-off the battery at one terminal, when the transmitting key at the other station breaks the circuit.

The accompanying drawings illustrate the invention.

Figure l is a complete view of the circuit and Fig. 2 shows a detail modification.

a and Z) are two terminal stations on a simple Morse circuit m, and c is an intermediate station; battery 9 is at one terminal and battery 10 at the other; at each terminal station there is a relay 0, a transmitting key 70, to break the circuit, a sounder z in a local circuit controlled by the relay 0, and an extra relay 6. At the intermediate station there is shown a similar main-line relay 1", a sounder s, a local circuit Z, having a local battery 13; in other words, the station 0 has only the ordinary and usual arrangement of apparatus. The instruments and apparatus at the terminal stations are substantially ldentlcal. Between stations as and 0 I have assumed the existence of an escape to ground, represented by conducting paths g, which rest on the line m, this is the condition arismg from branches of trees, especially when damp, as during foggy or rainy weather, as 1s well known to telegraph engineers. At a terminal station, sounder 2' has two windmgs, 20 and 2l,-on its core, which are inductively related and constitute an inductorlum; the coil 20 is in a local circuit with battery 11, and the front contacts 40 and 41 of relay 0. There is an extra or special relay e,having its coil in circuit 22, which includes the coil on relay 6, and the secondary coil, 21, on sounder i. The back contacts. of relay 6, shown at'5O and 51, are normally closed. The front contact of relay e is connected to ground through branch 60, for a purpose to be hereinafter described. There is a shunt or short-circuit on the secondary coil 21, formed by the back contacts 30, 31, through the connections 32 and 33.

The operation is as follows: If key 70, at station a, is opened, battery 10 is removed from circuit at the break point ofthe key; relay 0, at station 6, is demagnetized and breaks the local circuit of battery 11 in circuit with the primary coil 20, and an impulse or. extra current is induced in coil 20 which acts inductively to induce an impulse in secondary coil 21. This impulse is of short duration, but must be of suflicient in- I tensity to magnetize the coil of relay 6 at station Z) and attract armature 50, breaking contact with 51, opening the line m, so that battery 9 is removed from circuit, substantially coincident with the break due to key Z: at station a. The battery at both stations, having been thus removed, the escape at g is ineffective and the relay 7- releases its armature, for the reason that there is absolutely no current to magnetize 7*. Whether key 74 transmits a dot or a dash is imma terial, for the extra current in the coil 20 and the induced impulse in coil 21 would be a short impulse in either case. To avoid any effect on relay 6, due to the induced impulse on closing a key In, the circuit con taining the coil of relay 6 is disabled during the existence of said impulse; this is done by completing a shunt around the coil of relay 6 through an electro-magnetic switch, for which purpose contacts 30. and 31 of sounder i are employed, or it may be done, as shown in Fig. 2, by including saidcom tacts 30 and 31, in series, in said circuit; so

that said local circuit is opened during the 6, with its fixed andmovable contacts,'is also,

referred to as an electro-magneti'c switch, and the same is true ofthe sounder z' which has a fixed contact 31 and a movable contact 3Q.

VVhatI claim is:

1:. The combination, in a telegraph circuit, of main-line terminal battery sections, signaling instruments including main-line relay at terminal and intermediate stations, and at each terminal station an electro-magnetic switch having its front contacts in series in the line; an inductorium, a secondary coil local circuit including the coil of said switch, a primary coil local circuit including the front contact of the relay, and circuit connections and contacts in said secondary circuit soarranged that the making of the primary circuit due to signal transmission occurs only at an interval when the resulting impulse in the secondary circuit is inefiective.

2. In a circuit having terminal and in termediate stations provided with main-line relays and instruments adapted for, code signaling, the combination, at a terminal station, of a second relay device and an electro-magnet having two coils in inductive relation, a local, circuit including one of said coils and the front contacts of the main-line relay, a second local circuit containing the coil of said second relay and the second coil of said electro-magnet, connections includmg the back contacts of SELld second relay,

in series, in the main circuit, and a shunt branch on the terminals of said second coil including the back contacts of said electromagnet.

3. In a telegraph circuit, the combination at one. station of a main-line relay transmitting apparatus in said circuit at a second station, and at the first station an extra relay having its back contact points in series in the main circuit and its front contact connected to ground, and means whereby the operation of the main-line relay operates said extra relay.

4, In a telegraph circuit having a main battery in two separated sections, the combination with electro-magnetic receiving instruments at terminal stations and associated transmitting-devices, of means for ren -v dering one battery section ineffective when the other section is ineffective, said means including an electro-magnetic device, a device for generating a current impulse of short duration as compared with the signaling impulse, and an electromagnetic switch controlling the battery connection.

5. The combination, in a telegraph circuit, of receiving and transmitting apparatus, at separated stations, a pair of electro-magnetic switches each having its movable member connected to the main line and its fixed contact connected to ground, and means whereb the transmission of an elemental part of a code signal from either station breaks the circuit at the other station and completes the connection to ground.

6. The combination, in a telegraph circuit, of receiving relays and transmitting apparatus in said'circuit at separated points, an electro-magnetic switch atone station arranged, when operated, to render its mainline batteryineffective in said circuit, a local circuit including the coil ofsaid switch; a second electromagnetic switch having two coils in inductive relation, a local circuit including one of said coils and the main relay contacts, and local electrical connections between the contact points of said second electro-magnetic switch and the local circuit which includes the coils of the extra relay.

' JOHN J; GHEGAN. Witnesses JOHN C. SANDERS,

B. VANSIZE.

Copies of this-patentmay-be obtained for five cents each, by addressing theFGommissioner of Patents, Washington, D. C. 

